Vinyl chloride resins stabilized with metal compound-epoxy compound-phosphite combinations

ABSTRACT

HALOGEN CONTAINING RESINS, E.G., VINYL CHLORIDE RESINS AND DIOLEFIN POLYMERS, E.G., BUTADIENE-STYRENE RUBBER AND ACRYLONITRILE-BUTADIENE-STYRENE TERPOLYMER ARE STABILIZED E.G., AGAINST HEAT BY MIXED PHOSPHITES HAVING ONE ARYL GROUP HAVING AN ORTHO OR PARA DIECTING RING ACITIVATING SUBSTITUENT AND TWO ALKYL OR ALICYCLIC GROUPS. THE PREFERRED ALKYL OR ALICYCLIC GROUP IS CYCLOHEXYL. SOME OF THE COMPOUNDS, PARTICULARLY THOSE HAVING CYCLOHEXYL GROUPS, ARE NOVEL PER SE AS ARE COMPOUNDS IN WHICH THE ARYL GROUP HAS AN AMINO, AMIDO, ACETYL OR ACYLOXY SUBSTITUENT.

Patented Aug. 13, 1974 3,829,396 VINYL CHLORIDE RESINS STABILIZED WITHMETAL COMPOUND-EPOXY COMPOUND- PHOSPHITE COMBENATIONS Vincent Oakes, St.Helens, and David F. W. Cross, Liverpool, England, assignors toInterstab Limited, Liverpool, Lancashire, England No Drawing. Originalapplication Sept. 6, 1967, Ser. No. 665,725, now Patent No. 3,697,463.Divided and this application June 20, 1972, Ser. No. 264,481 Claimspriority, application Great Britain, Sept. 8, 1966, 40,114/66,40,115/66, 40,116/66 Int. Cl. C08f 45/58, 45/60, 45/62 U.S. Cl. 26023 XA2 Claims ABSTRACT OF THE DISCLOSURE Halogen containing resins, e.g.,vinyl chloride resins, and diolefin polymers, e.g., butadiene-styrenerubber and acrylonitrile-butadiene-styrene terpolymer are stabilized,e.g., against heat by mixed phosphites having one aryl group having anortho or para directing ring activating substituent and two alkyl oralicyclic groups. The preferred alkyl or alicyclic group is cyclohexyl.Some of the compounds, particularly those having cyclohexyl groups, arenovel per se as are compounds in which the aryl group has an amino,amido, acetyl or acyloxy substituent.

This application is a divisional application of co-pending applicationSer. No. 665,725, filed Sept. 6, 1967, and now U.S. .Pat. No. 3,697,463,granted Oct. 10, 1972.

The present invention relates to novel phosphites and to thestabilization of polymers with phosphites.

The preparation of monomeric and polymeric phosphites and their use tostabilize polyvinyl chloride, butadiene-styrene copolymers and otherhydrocarbon polymers is well known. Thus, Leistner Pat. 2,564,646 showsthe stabilization of vinyl resins with tris hydrocarbyl phosphites andHowland Pat. 2,419,354 and Hunter Pat. 2,733,226 show stabilization ofbutadiene-styrene copolymer and other rubbers with tris aryl phosphites.Friedman Pat. 3,047,608 shows that certain diphosphites are stabilizersfor natural rubber. Hechenbleikner "Pat. 2,839,- 563 shows that certainheterocyclic mono and diphosphites containing aryl groups arestabilizers for vinyl chloride resins and diolefin rubbers, whileHechenbleikner Pat. 2,847,443 discloses that mono to tetra phosphitescontaining aryl groups and pentaerythritol residues are similarlyuseful, and Hechenbleikner Pat. 2,841,606 discloses tetraaryl glycyldipliosphites have similar utility. Aryl bis polypropylene glycolphosphites and his aryl polypropylene glycol phosphites are old as shownin Friedman Pat. 3,009,939, but are not disclosed as useful instabilizing vinyl chloride resins or diolefin containing polymers. HuhnPat. 3,210,319 shows certain polymeric phosphites as stabilizers forvinyl chloride resins, and Huhn Pat. 3,061,583 shows such use formonomeric phosphites including mixed alkyl aryl (or methoxyphenyl orhydroxyphenyl) phosphites.

Larrison application Ser. No. 522,395, filed Jan. 24, 1966, now Pat. No.3,341,629, discloses polymers having the basic structure H(OROP)n whereR is the divalent residue of a dihydric phenol, aromatic dihydricalcohol or hydrogenated dihydric phenol, R is aryl, alkyl or haloaryland n is an integer. Larrison discloses such materials are useful tostabilize vinyl chloride resins and mono and diolefin containingpolymers. Sym. (aryl polypropylene glycol) polypropylene glycoldiphosphites are shown in Larrison application Ser. No.

436,349, filed Mar. 1, 1965, now Pat. No. 3,354,241, to have similaruses. Nelson Pat. 2,612,488 discloses that polymeric phosphites of theformula where R and R are aryl and arylene, respectively, are useful asstabilizers for synthetic rubbers.

As can be seen from the above cited patents, organic phosphites havebeen used for some time for the stabilization of vinyl chloride resinsand polymers such as butadiene-styrene rubber andacrylonitrile-butadiene-styrene terpolymer. One of the principalphosphites used commercially as a stabilizer is tris (nonyl phenyl)phosphite. The main drawback to this and similar phosphites is their lowhydrolytic stability under alkaline conditions. When phosphites areemployed for the stabilization of polymers such as the vinyl chlorideresins and diolefin polymers, for example, it is normal practice to addthe phosphite to the polymerization mixture which is alkaline. The poorhydrolytic stability of the phosphite can lead to rapid hydrolysis underthe conditions of use and thereby render the product useless. Althoughthis constitutes a major problem, the phosphites such as tris (nonylphenyl) phosphite have continued to be used widely because no otherphosphites of greater hydrolytic stability were known.

Accordingly, it is an object of the present invention to develop novelorganic phosphites of improved hydrolytic stability.

Another object is to stabilize butadiene-styrene compositions withorganic phosphites having improved hydrolytic stability.

An additional object is to stabilize acrylonitrile-butadiene-styreneterpolymers with organic phosphites having improved hydrolyticstability.

A further object is tostabilize halogen containing resins, especiallyvinyl chloride polymers, with organic phosphites having improvedhydrolytic stability.

Still further objects and the entire scope of applicability of thepresent invention will become apparent from the detailed descriptiongiven hereinafter; it should be understood, however, that the detaileddescription and specific examples, while indicating preferredembodiments of the invention, are given by way of illustration only,since various changes and modifications within the spirit and scope ofthe invention will become apparent to those skilled in the art from thisdetailed description.

It has now been found that these objects can be attained through thepreparation and use of certain organic mono and polyphosphites having atleast one aryl group having at least one ortho-para directing ringactivating substituent, and at least one cycloalkyl group. If the arylgroup has an amino, amido, carbonyl or carboxy substituent, in place ofthe cycloalkyl grou or groups there can be employed an alkyl group orgroups, although preferably a cycloalkyl group is present. There canalso be used aryl bis (poly lower alkylene glycol) phosphites asstabilizers for halogen containing resins and diolefin containingpolymers such as butadiene-styrene copolymer (e.g., :25) andacrylonitrile-butadiene-styrene terpolymer (e.g., 15:25:60).

The products of the present invent-ion can be incorporated in an amountof 0.01 to 20% into halogen containing vinyl and vinylidene resins.Preferably, the resin is a vinyl halide resin, specifically, a vinylchloride resin. Usually, the vinyl chloride resin is made from monomersconsisting of vinyl chloride alone or a mixture of monomers comprisingat least 70% vinyl chloride by weight. When vinyl chloride copolymersare stabilized, preferably the copolymer of vinyl chloride with anethylenically unsaturated compound copolymerizable therewith contains atleast 10% of polymerized vinyl chloride.

As the chlorinated resin there can be employed chlorinated polyethylenehaving 14 to 75%, erg, 27%, chlorine by weight, polyvinyl chloride,polyvinylidene chloride, polyvinyl bromide polyvinyl fluoride,copolymers of vinyl chloride with 1 to 90%, preferably 1 to 30%, of acopolymerizable ethlenically unsaturated material such as vinyl acetate,vinyl butyrate, vinyl benzoate, vinylidene chloride, diethyl fumarate,diethyl maleate, other alkyl fumarates and maleates, vinyl propionate,methyl acrylate, Z-ethylhexyl acrylate, butyl acrylate and other alkylacrylates, methyl methacrylate, ethyl methacrylate, butyl methacrlate,and other alkyl methacrylates, methyl alpha chloroacrylate, styrene,trichloroethylene, vinyl ethers such as vinyl ethyl ether, vinylchloroethyl ether and vinyl phenyl ether, vinyl ketones such as vinylmethyl ketone and vinyl phenyl ketone, l-fluoro-l-chloroethylene,acrylonitrile, chloroacrylonitrile, allylidene diacetate andchloroallylidene diacetate. Typical copolymers include vinylchloride-vinyl acetate (96:4 sold commercially as VYNW), vinylchloride-vinylacetate (87:13), vinyl chlo ride-vinyl acetate-m'aleicanhydride (86: 13: 1), vinyl chloride-vinylidene chloride (95:5), vinylchloride-diethyl fumarate (95:5 vinyl chloride-trichloroethylene (95:5),vinyl chloride-Z-ethylhexyl acrylate (80:20). The organic phosphites ofthe present invention are particularly useful as secondary heatstabilizers for vinyl chloride polymers such as polyvinyl chloride.Vinyl chloride polymers and copolymers by virtue of being thermoplastichave to be softened by application of heat during fabrication orcalendering, extruding, injection molding or similar techniques. Thisheating is limited in degree and duration by the tendency of the resinsto decompose which manifests itself in a deterioration in the physicalproperties of the resin and a severe darkening in color which, if notcorrected, would prohibit the use of the resins for light colored andtransparent articles. In many instances, it is also necessary tostabilize the resin against weathering from sunlight and rain inarticles which have to be subjected to outdoor exposure.

The phosphites of the present invention can be used with virtually allof the broad classes of compounds known in the literature for use asstabilizing agents in vinyl chloride containing polymers.

Thus, the vinyl chloride resin can contain 0.1 to of lead salts such asbasic white lead carbonate, di, tri and tetra basic lead sulfate, leadstearate and dibasic lead phosphite.

Of course, there can also be added to the vinyl chloride formulationsGroup II and III metal salts in an amount of 0. 1 to 10% as isconventional in the art. The most common metals used are barium,cadmium, calcium, zinc, aluminum and magnesium and the soaps are formedfrom readily available higher fatty acids such as lauric acid andstearic acid and from other acids such as maleic acid, phthalic acid,benzoic acid and phenols such as phenol per se and alkyl phenols.Typical salts include barium laurate, cadmium laurate, zinc stearate,calcium Z-ethylhexoate, barium nonylphenolate, barium octylphenolate,zinc octoate, barium stearate, aluminum stearate, magnesium stearate,calcium phthalate, calcium benzoate, and cadmium maleate.

The metal soaps in normal practice are employed in mixtures such asbarium-cadmium, barium-cadmium-zinc, barium-zinc, calcium-zinc andcalcium-magnesium-zinc.

Also, there can be employed 0.1 to 10% of organotin compound stabilizerssuch as dialkyltin oxides and salts, e.g., dialkyltin dilaurates such asdibutyltin dilaurate, dioctyltin dilaurate, dialkyltin maleates such asdibutyltin maleate, dioctyltin maleate. dibutyltin oxide, dioctyltinoxide, dialkyltin mercaptides, e.g., dioctyltin di(octylthioglycolate),dibutyltin di(octyl-thiopropion-ate), dialkyltin cryptomercaptides, bis(tribu-tyltin) oxide, etc.

Compounds within the classes of lead salts, metal soaps and organotincompounds are recognized as primary stabilizers for vinyl chloridecontaining polymers. While the organic phosphites are not highly activeby themselves as stabilizers, they exhibit synergism with the primarystabilizers, particularly with the metal soaps, as they delayconsiderably the initial on-set of color formation. It has beensuggested that the organic phosphites function by their ability tochelate undesirable metal chlorides which are formed during thestabilization of the polyvinyl chloride, or other vinyl chloride resin,by the primary stabilizers. Thus, e.g., stabilization of polyvinylchloride with a mixed barium-cadmium laurate would lead to the formationof barium-cadmium chloride which known to. promote degradation of thepolyvinyl chloride. The presence of the organic phosphite chelates thismetal chloride and, therefore, renders it innocuous.

In order to achieve stabilization, the organic phosphites may be addedto the vinyl chloride containing polymer in amounts up to one part perhundred of resin. It is also standard practice, however, to blendtogether the organic phosphite and metal soap in predeterminedproportions along with other synergistic additives if desired and soform stabilization systems which are usually liquids. Triphenylphosphite was the first oragnic phosphite to be used for this purposeand has continued to be regarded as a standard secondary stabilizer forpolyvinyl chloride. Trialkyl phosphites such as tridecyl phosphite havealso been used as secondary stabilizers.

The phosphites according to the invention exhibit far superiorproperties over the phosphites hitherto used.

A method according to the invention for preparing organic phosphites asspecified above comprises heating a triaryl phosphite having at leastone ortho-para directing ring activating substitutent with one or twomolar pro portions of an alcohol in the presence of an alkaline catalystand distilling off the liberated phenol.

Another method for preparing the organic phosphites comprises heating atrialkyl phosphite with from one to three molar proportions of a phenolhaving at least one ortho-para directing ring activating substituent inthe presence of an alkaline or secondary phosphite catalyst, anddistilling off the liberated alcohol.

The preparation of the compounds specified may be carried out asfollows: 1

METHOD A Substituted phenol (3.1 g. mols) was stirred in a glass reactorand phosphorus trichloride (1.0 g. mols) added over a period ofapproximately 30 minutes at a temperature of 50 C. Vacuum was thenapplied to the stirred mixture which was heated to C. and maintainedthere for a period of approximately one hour. During this period most ofthe hydrogen chloride formed was removed. The temperature was thenincreased to 200 C. over a period and the excess phenol-present in thereaction mixture stripped out. The still residue was then cooled to C.,tested for acidity and if greater than 1 was treated with either sodiumcarbonate or magnesium oxide, stirred for 15 minutes and filtered toafford the desired triaryl phosphite in virtually quantitative yields.

METHOD B Tri(substituted aryl) phosphite (1 g.. mol) and alcohol (1 g.mol or 2 g. mols) were heated together for approximately one hour at C.in the presence of 0.2 g. of an alkaline catalyst, e.g., sodium hydride.Vacuum was then applied to the system and the temperature raised to 200C. During this period phenol started to distill out from the mixture andthe distillation was continued until no more phenol was evolved. A smallquantity of filter aid was then added and the mixture filtered to affordthe desired mono-alkyl diaryl phosphite or dialkyl monoaryl phosphite invirtually quantitative yield.

METHOD C Trialkyl phosphite (1 g. mol) (e.g., either trioctyl phosphiteor tri-isodecyl phosphite) and substituted phenol (3.1 g. mols) wereheated together in the presence of either 0.2 g. of sodium hydride or0.3 g. of diphenyl phosphite at a temperature of 140 C. for one hour.Vacuum was then applied to the reaction mixture which was heated to 200C. so as to remove the alcohol by distillation. When all the alcohol hadbeen removed, the still residue was cooled to 100 C. and treated withfilter aid and filtered so as to afford the triaryl phosphite invirtually quantitative yield.

By reducing the molar proportion of substituted phenol in thispreparation, partially substituted products could be obtained in a.manner similar to that described in Method B. V The main choice betweenusing Method B or Method C depended on the relative boiling points ofthe substituted phenol and the alcohol in question. if the phenol had alower boiling point, then Method B was used. If the alcohol had thelower boiling point, then Method C was used. As an additional variation,Method B could also be used for making substituted phenyl phosphitesfrom triphenyl phosphite by introducing the substituted phenol in placeof the alcohol described in Method B.

Examples of phosphites prepared by the above techniques are given inTable 1.

TABLE 1 Refractive Product Method index Bis p-methoxyphenyl isodecylphosphite B 1. 5225 p-Methoxyphenol diisodecyl phosphite B 1. 4830p-Dilrziethylaminomethyl phenyl diisodeoyl phos- C 1. 4992 phi e.

Catechyl isode cyl phosphite B 1. 5100 t-Butylcatechyl isodeeylphosphite B Bis p-hydroxyphenyl isodecyl phosphite. B 1. 5325p-Hydroxyphenyl diisodecyl phosphite B 1. 4910 o-Hydroxyphenyldiisodecyl phosphite B 1. 4908 2-methyl-4-carboxylphenyl diisodecylphosphite B 1. 4915 p-Acetamidophenyl diisodecyl phosphite B 1. 5009 pAcetylphenyl diisodecyl phosphite 1. 4038 g-Acetoxyphenyl diisodecylphosphite B 1. 4945 is p-nonylphenyl polypropylene glycol moleeu- B 1.4914 lar weight 425 phosphite. p-Nonylphenyl bis (polypropylene glycolmolecu- B 1. 4698 lar weight 425) phosphite.

-Nonyiphenyl di(cyclohexyl) phosphite O 1. 5152 is (p-nonylphenyl)cyclohexyl phosphite C 1.5220 p-t-Butylphenyl di(cyclohexyl) phosphiteC 1. 5241 Bis (2, 4-di-t-buty1phenyl) cyclohexyl phosphi e C 1. 5246 2,4-di-t-buty1phenyl di(cyclohexyl) phosplute C 1. 5193 The compounds setforth supra were liquids. The refractive indices were determined at 20to 25 C.

Illustrative examples of making compounds are set forth below.

Unless otherwise indicated, all parts and percentages are by weight.

Example 1 1 g. mol of tri cyclohexyl phosphite and 1 g. mol ofp-nonylphenol were heated in the presence of 0.2 gram of sodium hydrideat 140 C. for one hour. Vacuumv was then applied and the mixture heatedto 200 C. to remove all of the cyclohexanol formed. The still residuewas cooled to 100 C. and filtered to give p-nonylphenyl di (cyclohexyl)phosphite as the liquid residue.

Example 2 The procedure of Example 1 was employed but there were used 2g. mols of the nonyl phenol to give his (pnonylphenyl) cyclohexylphosphite as the liquid residue.

Example 3 The procedure of Example 1 was employed but the nonyl phenolwas replaced by 1 g. mol of p-t-butylphenol to give p-t-butylphenyldi(cyclohexyl) phosphite as the liquid residue.

Example 4 The procedure of Example 1 was repeated but in place of thenonylphenol there was used 1 g. mol of 2,4-di-t- 6 butylphenol to form2,4-di-t-butylphenyl di(cyclohexyl) phosphite as the liquid residue.

Example 5 I,

The procedure of Example 4 was employed but there was used 2 g. mols ofthe 2,4-di-t-butylphenol to form bis (2,4-di-t-butylphenyl) cyclohexylphosphite as the liquid residue.

Example 6 1 g. mol of tri (p-nonylphenyl) phosphite was heated with 1 g.mol of polypropylene glycol molecular weight 425 for one hour at C. inthe presence of 0.2 gram of sodium hydride. Vacuum was applied and thetemperature raised to 200 C. The phenol was distilled from the mixture,the residue filtered and his (p-nonylphenyl) polypropylene glycol 425phosphite recovered as the liquid residue.

Example 7 The procedure of Example 6 was repeated using 2 g. mols of thepolypropylene glycol 425 to obtain p-nonylphenyl bis (polypropyleneglycol 425) phosphite as the liquid residue.

In place of the phosphites prepared in Examples 6 and 7 there can beprepared and used corresponding phosphites from polyalkylene glycolssuch as diethylene glycol, dipropylene glycol, polypropylene glycol 2025and the like.

While there were employed p-nonylphenol, 2,4-di-tbutylphenol andp-t-butylphenol as the ortho-para directing ring activating substituentcontaining phenols in the above examples, there can be used otherphenols having such activating groups, e.g., o-cresol, p-cresol,2,4-xylenol, p-secondary amyl phenol, p-t-amylphenol, o-t-butylphe nol,p-dodecylphenol, p-octadecylphenol, p-acetamidophenol, p-aminophenol,p-acetylphenol, 2-methyl-4-carboxyphenol, p-acetoxyphenol,p-methoxyphenol, hydroquinone, catechol, or there can be used as thearomatic phosphites for the ester interchange materials such as tris (pnonylphenyl) phosphite, tri (p-octylphenyl) phosphite, tris(p-dodecylphenyl) phosphite, tris (p-acetoxyphenyl) phosphite, tris(p-octadecylphenyl) phosphite, tris (p-tbutylphenyl) phosphite, tris(o-t-butylphenyl)phosphite, tris (p-cresyl) phosphite, tris(2,4-xylenyl) phosphite.

The enhanced hydrolytic stability of many of the compounds used in thepresent invention makes them of particular value in the stabilization ofdiolefin polymers such as rubbery butadiene-styrene copolymer (e.g.,60:40 or 75:25) of acrylonitrile-butadiene-styrene terpolymer (ABS,e.g., 1020% acrylonitrile, 25 to 60% butadiene and 20 to 60% styrene)such as 15% acrylonitrile, 25% butadiene and 60% styrene.

Tris (nonylphenyl) phosphite has been used extensively as a stabilizerfor butadiene-styrene rubber and for ABS. The main drawback to this andsimilar compounds is its low hydrolytic stability under alkalineconditions. When using these phosphites for the stabilization ofpolymers, it is normal practice to add the phosphite to thepolymerization mixture which is alkaline. The poor hydrolytic stabilityof the phosphite can lead to rapid hydrolysis under the conditions ofuse and thereby render the product useless. Although this constitutes amajor problem, the phosphites such as tris (nonylphenyl) phosphite havecontinued to be used widely because no other phosphites of greaterhydrolytic stability were known. Compounds of the invention whichcontain at least one alkyl, substituted alkyl, alkoxyalkyl or cycloalkylgroup and which have improved hydrolytic stability are valuable asstabilizers for butadiene-styrene rubber and -ABS terpolymers. When analkyl group is present, it usually has at least six carbon atoms andmore preferably ten carbons and can be as high as eighteen carbon atoms.Thus, there can be used as stabilizers for the diolefin polymersp-methoxy- 7 phenyl diisodecyl phosphite, p-methoxyphenyl di(cyclohexyl)phosphite, bis (p-methoxyphenyl) hexyl phosphite, p-ethoxyphenyldioctadecyl phosphite, as well as the other phosphites disclosed herein.There are normally used 0.1 to parts of phosphite per 100 parts ofdiolefin polymer (butadiene-styrene rubber oracrylonitrile-butadiene-styrene terpolymer) In order to determine thehydrolytic stability of the phosphites, the following test was carriedout. A recording pH meter was calibrated at pH 7 and pH 9.2 (at C.). Theprobe was positioned in a S-neck flask containing 100 grams of 0.003molar aqueous caustic soda solution. The soltuion was stirred. Thesolution had a pH of 113:0.1 at ambient temperature. 5 grams of thephosphite to be tested were dissolved in 50 grams of neutralisopropanol. The phosphite solution was added to the caustic solution, acondensor and thermometer fitted to the flask and the flask lowered intoa thermostatically controlled water bath at 50 C. :-0.5 C. The mixturewas constantly stirred and the time required for the solution to reachpH 7 was measured.

Using this technique several of the new phosphite stabilizers, as wellas several known phosphite stabilizers, were examined. The knownstabilizers were triphenyl phosphite, bis (p-nonylphenyl) phenylphosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite andsymmetrical hydrogenated bisphenol A phenyl hydrogenated bisphenol Adisphosphite (sym. HBPA phenyl HBPA diphosphite). The results are setforth in Table 2.

TABLE 2 Time to reach p-nonylphenyl bis polypropylene glycol 425phosphite 24.75 Bis (p-nonylphenyl) polypropylene glycol 425 phosphite3.75 2,4-di-t-butylphenyl diisodecyl phosphite 15.5Tetrakis-(2,4-di-t-butylphenyl) polypropylene glycol 425 phosphite 10.6

As a general rule, it appeared that the compounds containing the mostactive substituents performed better in polyvinyl chloride than othercompounds. Thus, for example, compounds containing the methoxy ortertiary butyl group attached to the phenyl group were extremelyeffective. Phosphites containing three such activated aryl groups werenot as effective as secondary stabilizers as compounds containing onlyone or two such groups. The cyclohexyl group is the preferred aliphaticgroup. Higher alkyl groups such as decyl are more useful than loweralkyl groups, e.g., methyl or butyl, in the phosphites.

It has also been found that a mixture of a trisubstituted aryl phosphitewith a trialkyl phosphite in molar proportions of either 2:1 or 1:2would function almost identically to a di-substituted aryl alkylphospite or mono-substituted aryl dialkyl phosphite, respectively. Itappears from this that under the conditions of fabrication in thepolyvinyl chloride, ester interchange is taking place with the resultantformation of the mixed aryl alkyl phosphites which have been found to bethe more effective.

Compounds according to the invention were examined as secondarystabilizers for polyvinyl chloride by mixing in the formulationsdescribed for 5 minutes on a two roll laboratory mill at 155 C. Theresulting hides were then sheeted at 0.050 inch thickness and heated inan aircirculating oven at 185 C. Inspection samples were withdrawn atfixed intervals and examined for color development. The colors wererated 'on the following scale:

1 Colorless. 2 Faint yellow. 3 v Slight Yellow. 4- Yellow. -5 Deepyellow. 6 Amber. 7 Brown. 8 Dark Brown. 9 Black.

Example8 Parts Polyvinyl chloride (Corvic D 65/6 having a K value v of65) Diisooctyl phthalate 50 Epoxy soyabean oil 5 Stanclere 1200(barium-cadmium laurate soap) 2 Phosphite 0.5

Milling time (minutes) Compound 30 e0 90 Tri-isodeeyl phosphite 1 2 2 68 9 Diphenyl isodecyl phosphite 1 2 4 4 7 Bis (p-methoxyphenyl) isodecylphosphite 1 1 3 3 4. Tris (p-methoxyphenyl) phosphite- 2 2 2 4 4 4 Tris(p-methoxyphenyl) phosphite,

0.35 1 1 3 3 4 Tris isodecyl phosphite, 0.15

Example 9 Parts Polyvinyl chloride (Corvic D 65/ 6) 100 Diisooctylphthalate 45 Epoxy soyabean oil 5 Stanclere 1200 2 Minutes CompoundAmount 20 40 60 80 120 Diphenylisodecyl phosphite 0.43 1 3 4 7 Bis(p-methoxyphenyl) isodecyl phosphite 0. 43 1 2 2 3 4 p-Methoxyphenyldiisodecyl phosphite 0.46 1 1 1 3 4: pt-Butylphenyl dipropylene glycolphosphite O. 43 1 1 1 3 6 In this example the phosphite additions weresuch that the phosphorus content of the mix was constant.

Example 10 Parts Polyvinyl chloride 100 Diisooctyl phthalate 50 Epoxysoyabean oil 5 Stanclere 1200 2 Phosphite 0.5

Minutes Compound 20 40 60 80 100 120 Diphenyl isodecyl phosphite 1 1 2 26 7 p-Methoxyphenyl diisodecyl phosphite 1 1 1 3 3 p-Hydroxyphenyldiisodecyl phos- I phite 1 1 1 1 3 3 Bis (polypropylene glycol 425)pnonylphenyl phosphite 1 1 2 2 6 6 Tetrakis p-nonylphenyl polypropyleneglycol 425 phosphite 1 1 1 2 4 5 Totrakis p-nonylphenyl tripropyloneglyeyl diphosphite 1 1 1 1 3 3 Example 11 Parts Polyvinyl chloride 100Diisooctyl phthalate 47 Epoxy soyabean oil 3 Barium-cadmium laurate(2:1) 2, Phosphite 0.5

, 7 Example 15 p 7 v t I" L 7 Parts CbmPmmd v, 7 8 7 PolyvinylchlorideCorvic D 6 6) 100 1T)l i c clo i l h ls hite u; 1 ,2 g s gh a e e --'7-1p eny.1so eey p as]; 3 X poxy soya ean o1 zg?zi ;s;i--- 1 2 I 5 5Tribasic lead sulfate 3 h 1 1 2 4 5 v Di fi ylohexyl) 1 1- '1. 1. '2 '3Phosphate 722 3355 igjg ggq ggggq Because of the opacity imparted to theresin by the basic Phosphite 1 1 1 2 2 lead sulfate (the primarystabilizer) a different color cod- Di (cyclohexyl) 2, 4-d1-t-butylv aphenyl phosphita 1 1 1 1 2 1 mg to that 1n the foregoing examples wasemployed as Big 1,4-fiii-t-1bfitylpheny1) cyc10-, 1 1 V 1 l 1 2 f ll I e1 white Example 2 p yellow 7 Parts 3 yellow Polyvinyl chloride (Corvic D65/6) 100 Pala Orange Diisooctyl phthalate 50 orange Epoxy soyabean oil3 6 Pale orange brown Barium-cadmium laurate' 2 7 orange brown 2,4di-tbutylphenyl di (cyclohexyl) 1 phosphite As indicated Mmutes2,4-d1-t-butylphenyldi (cyclohexyl) phosphite D'hl'dlhhit -Q135677 Tune(mmutes) T; s:d gcy 1 gh% s%h i ie?R -2" 4 e 7 7 7 40 80 mo 140-yitaziiitti .fififiiti if ff; 2 3 5 6 7 1 2 4 5 9 9 B15 (p-nonylphenyl)cyclohexyl 2 4 5 8 9 phosphite 1 2 4 6 7 7 1 1 2 3 5 9 p-Nonylphenyl d1(cyclohexyl) 1 1 1 3 5 9 phosphite 1 2 3 4 7 7 1 1 1 3 5 9p-t-butylphenyl d1 (cyclohexyl) 1 1 1 3 4 8 p q p 1 2 3 4 6 6 1 1 1 2 38 2, 4di-t-butylphe nyl d1 (cyclo- 1 1 1 1 3 5 hexyl) phosphite 1 2 3 57 7 1 1 1 1 2 5 B13 (2, 4-di-t-butylpheny1) cyclo- 1 1 1 1 2 4 hexylphosphite 1 2 3 5 7 7 Diphenylisodecyl phosphite The examples provideadequate proof that the presence 1 2 3 6 7 9 of the activated aryl groupin the phosphite molecule con- 1 1 2 5 0 fers additional stability tothe polyvinyl chloride composition. The best results appear to beobtained when only ple 13 one activated aryl group is present.

Parts The following examples illustrate formulations suit- Polyvinyl hlid (C i 1) 65/6) 100 able for giving heat stability to butadiene-styrenecopoly- Diisooctyl phthalate 50 met and to acrylonitrile-butadienestyrene terpolymer. Epoxy soyabean il 3 In the examples thebutadiene-styrene copolymer was Calcium-zinc stearate (2:1) 2 75125 andthe ABS terpolymer was 15:25:60. In the fol- Phosphjte 0,5 lowingexamples the phosphite was milled into the dickfin polymer on a rubbermill. However, the phosphite can Minutes be added to an aqueous emulsionof the polymer if de- Compound 20 40 so so sired Tricyclohexyl phosphite1 2 4 9 Examp 1e 16 gipheryl islodficyl lpilzosphiteun g i g Parts pl\i:5 t l1o?pfi:an f di-igodecy1 phosphite 1 1 2 9 Butadlqne-Styrenecopolymer 100 p-Nonylphenyl di (cyclohexyl) phosphite 1 1 2 9 Ph phlt1.67 p-t-Butylphenyl di (cyclohexyl) phosphit 1 1 2 9 I I 'fi pbutylphenyl (may Illustrative phosphltcs wh1ch are useful 1n thisexample exyl) phosphite 1 1 2 9 Bis (2,4-di-t-butylphenyl)cyclohexylphosphite- 1 1 2 9 r 1 y y py p y p p d1 (cyclohexyl)p-t-butylphenyl phosphite, (c) di (cyclo- Example 14 hexyl)2,4-di-t-butylphenyl phosphite, (d) cyclohexyl bis Parts (p-nonylphenyl)phosphite, (e) cyclohexyl bis (p-t-but- Polyvinyl chloride (Corvic D65/6) 100 tylphenyl) phosphite, (f) cyclohexyl bis (2,4-di-t-butyl-Diisooctyl phthalate 50 phenyl) phosphite, (g) p-methoxyphenyldiisodecyl phos- Epoxy soyabean oil 3 phlte, (h) p-methoxyphenyl d1(cyclohexyl) phosphite, Dibutyltin bis (isooctyl fl-mercapto propionate)1 (i) py yp y diisodecyl p p (i) py y- Phosphite 0,5 phenyl di(cyclohexyl) phosphite, (k) p-nonylphenyl bis (diproylene glycol)phosphite, (1) p-nonylphenyl bis Tlme (minutes) (polypropylene glycol425) phosphite, (m) p-tamyl- Compound 20 40 60 so 100 120 phenyl d1(cyclohexyl) phosphite. T 1 h 1 h hit 1 1 2 a 4 6 hlfiiifhhl d5151108211179- 1 1 2 2 4 6 Example 17 Triisodecyl phosphite 1 1 2 2 4 6Parts 1 1 1 2 4 5 Acrylonitrile-butadiene-styrene terpolymer IBish(pilrfinylphenyl) cyclohexyl 1 1 1 2 2 4 (15225260) 100 OS 6 p-l lomlphenyl d1 (cyclohexyl) Phosphlte 2 phosphite 1 1 1 2 3 4p4j-gutsillipthgnyl (1i (cyclohexyl) 1 1 1 2 3 5 Illustrative phosphiteswhich are useful 1n this ex- P 9 6 ample are (a) di (cyclohexyl)p-nonylphenyl phosphite 24d1-t-btlh 1 d 1- 3 ex l) h i 1ffl -l--. iiif 11 1 1 2 4 (b) d1 (cyclohexyl) p-t-butylphenyl phosphite, (c) d1 5 tg g ifig f fg fl ft 1 1 1 1 2 4 7 (cyclohexyl) 2,4-di-t-butylphenylphosphite, (d) cyclohexyl bis (p-nonylphenyl) phosphite, (e) cyclohexylbis

